Northrup Grumman has been powering higher, and one investor is upping the ante.

optionMONSTER's Heat Seeker monitoring program detected the purchase of 5,000 August 72.50 calls for $1.18 and the sale of 2,500 April 70 calls for $0.31. Volume was below open interest at the lower strike, which suggests that an existing position was closed and rolled forward in time.

The trade is especially bullish because the investor doubled the number of contracts owned and put an additional $512,500 to work. He or she probably bought the 70s earlier in the month when the defense contractor was lower and now wants to adjust it before time decay erodes their value. (See our Education Section .)

NOC fell 0.21 percent to $67.91 yesterday. The stock has been trading in a range since last summer, but has been grinding higher this month after finding support bear its 200-day moving average.

Total option volume was 12 times greater than average in the session, according to Heat Seeker. Calls outnumber puts by a bullish 229-to-1 ratio.

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